Low dose involved field radiation (IFRT) or no further treatment following complete response to initial chemotherapy in young adult (YA) patients 16-21years of age with Hodgkin's disease (HD): The Children's Cancer Group (CCG) experience

Complete response was defined as no visible disease on restaging CT scans OR >70% reduction in tumor volume and conversion of all sites of gallium positive disease to gallium negative.

Results

Patients were 16-21 years old. 67% were stage I,II, 40% had bulk disease, 86% had nodular sclerosing HD and 76% had ESR >20.

Of 227 enrolled patients, 215 completed protocol chemotherapy. 168 achieved a CR while 46 had a PR. 60 patients were randomed to receive IFRT while 56 patients were randomized to no further therapy.

Overall 5 yr EFS was 83% and OS was 93%

By treatment arm, 5 yr EFS was 93% and 76% (p=0.013) for IFRT and no IFRT, respectively. Corresponding 5 yr OS was 100% and 93% (p=0.056)

Failures occurred early. In the no IFRT arm, 90% of failures occurred within what would have been treated by IFRT. Most of these failures were seen in patients receiving only 4 cycles of chemotherapy.

Author's Conclusions

Adolescent HD patients are more likely to have bulk disease, B symptoms and nodular sclerosing histology than younger patients, perhaps making them more likely to benefit from radiation.

EFS was significantly improved in this group of patients with the addition of IFRT.

A trend towards improved OS with IFRT was seen (p=0.056).

B symptoms and bulk disease were associated with a higher risk of recurrence.

Clinical/Scientific Implications In this study, adolescent patients were seen to have more high risk features than their younger counterparts. Perhaps because of this, improved outcomes were seen with the addiation of 21 Gy IFRT. Better risk stratification is needed. In the no IFRT arm, most failures occurred in patients receiving only 4 cycles chemo. If these patients could be prospectively identified and given more chemotherapy, perhaps RT could be avoided safely. However, until better risk stratification becomes available and further randomized studies are completed, low dose IFRT will remain a part of the standard treatment of adolescent HD patients.